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 A078653 a(n) = prime(k) where k = n-th prime congruent to 1 mod 4. 2
 11, 41, 59, 109, 157, 179, 241, 283, 367, 461, 509, 547, 599, 617, 773, 859, 919, 1031, 1087, 1171, 1201, 1447, 1471, 1523, 1621, 1723, 1787, 1823, 1913, 2081, 2099, 2269, 2351, 2381, 2549, 2683, 2719 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Sum 1/a(n) appears to converge albeit slowly. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 FORMULA a(n) = A000040(A002144(n)). [Bruno Berselli, Aug 14 2012] MATHEMATICA With[{pc14=Select[Prime[Range[100]], Mod[#, 4]==1&]}, Flatten[Table[ Prime[ Take[ pc14, {n}]], {n, 40}]]] (* Harvey P. Dale, Aug 12 2011 *) PROG (PARI) pip(n, m, r) = {sr=0; forprime(x=3, n, if(x%m == r, v=prime(x); sr+=1.0/v; print1(v" "); ) ); print(); print("m="m" r="r" sr="sr); } (Magma) [NthPrime(n): n in PrimesUpTo(400) | n mod 4 eq 1]; // Bruno Berselli, Aug 14 2012 CROSSREFS Cf. A006450, A078654. Sequence in context: A350006 A122015 A192820 * A040167 A040170 A333085 Adjacent sequences: A078650 A078651 A078652 * A078654 A078655 A078656 KEYWORD nonn,easy AUTHOR Cino Hilliard, Dec 14 2002 EXTENSIONS Offset changed from 0 to 1 by Vincenzo Librandi, Aug 14 2012 STATUS approved

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Last modified December 5 10:56 EST 2023. Contains 367589 sequences. (Running on oeis4.)